As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: APU AGENT DISCHARGE LIGHT ILLUMINATED. MAINTENANCE PERFORMED AN OPERATIONAL AND VISUAL CHECK OF THE APU FIRE PROTECTION SYSTEM PER AMM 26-22-00 WITH NO DEFECTS NOTED AND THE AGENT DISCHARGE LIGHT WAS NOT ILLUMINATED.